[Rails5] Pass class references instead of strings to middleware builder

See merge request gitlab-org/gitlab-ce!19729

Resolve "`MigrateUploadsWorker` is doing N+1 queries on migration"

Closes #47408

See merge request gitlab-org/gitlab-ce!19547

Migrate compare_source_branch to use only Gitaly

Closes gitaly#771

See merge request gitlab-org/gitlab-ce!19700

Restoring user v3 endpoint

Closes #47565

See merge request gitlab-org/gitlab-ce!19661

Resolve "Microsoft Teams notification for pipelines do not work"

Closes #42342

See merge request gitlab-org/gitlab-ce!19632

Added with_stats option to GET /projects/:id/repository/commits (API)

See merge request gitlab-org/gitlab-ce!19484

Resolve "Use one column form layout on Admin Area Settings page"

Closes #44674

See merge request gitlab-org/gitlab-ce!19673

It fixes Rails 5.0 deprecation flooding like:

```
DEPRECATION WARNING: Passing strings or symbols to the middleware builder is deprecated, please change
them to actual class references.  For example:

  "::Gitlab::Middleware::ReadOnly" => Gitlab::Middleware::ReadOnly

 (called from <top (required)> at /builds/gitlab-org/gitlab-ce/config/environment.rb:11)
DEPRECATION WARNING: Passing strings or symbols to the middleware builder is deprecated, please change
them to actual class references.  For example:

  "ActionDispatch::Static" => ActionDispatch::Static

 (called from <top (required)> at /builds/gitlab-org/gitlab-ce/config/environment.rb:11)
DEPRECATION WARNING: Passing strings or symbols to the middleware builder is deprecated, please change
them to actual class references.  For example:

  "Gitlab::Testing::RequestBlockerMiddleware" => Gitlab::Testing::RequestBlockerMiddleware

 (called from <top (required)> at /builds/gitlab-org/gitlab-ce/config/environment.rb:11)
DEPRECATION WARNING: Passing strings or symbols to the middleware builder is deprecated, please change
them to actual class references.  For example:

  "ActionDispatch::Static" => ActionDispatch::Static

 (called from <top (required)> at /builds/gitlab-org/gitlab-ce/config/environment.rb:11)
DEPRECATION WARNING: Passing strings or symbols to the middleware builder is deprecated, please change
them to actual class references.  For example:

  "Gitlab::Testing::RequestInspectorMiddleware" => Gitlab::Testing::RequestInspectorMiddleware

 (called from <top (required)> at /builds/gitlab-org/gitlab-ce/config/environment.rb:11)
```

Resolve "Groups > Members > No padding between dropdowns/input"

Closes #46702

See merge request gitlab-org/gitlab-ce!19724

Resolve "Participants tooltip is cutoff when too close to the window edge"

Closes #47551

See merge request gitlab-org/gitlab-ce!19669

Resolve "Project search in navbar is missing top margin in dev.gitlab.com"

Closes #47773

See merge request gitlab-org/gitlab-ce!19718

Clean up stale Prometheus metrics in before_exec unicorn hook

See merge request gitlab-org/gitlab-ce!19683

Resolve "Alignment of labels within two column layouts for radio and check boxes"

Closes #47265

See merge request gitlab-org/gitlab-ce!19671

Fix labels too large

Closes #47499 and #47762

See merge request gitlab-org/gitlab-ce!19640

Fixed IDE jobs empty state showing when loading

Closes #47766

See merge request gitlab-org/gitlab-ce!19706

Ensure MR diffs always exist in the PR importer

Closes #47312

See merge request gitlab-org/gitlab-ce!19704

Find and mark more Git disk access locations, part 2

See merge request gitlab-org/gitlab-ce!19437

mergeError message has been binded using v-html directive

See merge request gitlab-org/gitlab-ce!19058

Closes #47766

Replace ... with ellipsis in placeholders

See merge request gitlab-org/gitlab-ce!19627

Bumping gitlab-gollum-lib and gitlab-gollum-rugged_adapter

Closes #47577

See merge request gitlab-org/gitlab-ce!19641

i18n: document how to use links without splitting sentences

See merge request gitlab-org/gitlab-ce!19682

Add CI_{PIPELINE,JOB}_URL

See merge request gitlab-org/gitlab-ce!19618

Closes #42342

In rare cases it could happen that an MR was created, but creating the
MR diffs somehow failed (e.g. due to an error). This commit adds an
additional check to make sure MR diffs are always present when importing
GitHub pull requests.

Merge branch 'blackst0ne-rails5-actionview-missingtemplate-in-spec-features-projects-wiki-user_views_wiki_page_spec-rb' into 'master'

Resolve "[Rails5] `ActionView::MissingTemplate` in spec/features/projects/wiki/user_views_wiki_page_spec.rb"

Closes #47738

See merge request gitlab-org/gitlab-ce!19685

Resolve "[Rails5] `ActionView::MissingTemplate` in spec/features/projects/wiki/user_views_wiki_page_spec.rb"

Add CI job to check Gemfile.rails5.lock

See merge request gitlab-org/gitlab-ce!19605